Integrating computational and experimental insights into osmolyte-driven activation of Geobacillus kaustophilus L-asparaginase for acrylamide mitigation

Abstract

Osmolytes play a critical role in enhancing the stability and activity of enzymes for industrial applications. This study systematically investigated the effects of various osmolytes on the activity, optimal pH, temperature, stability, metal ion effects, storage, and acrylamide mitigation performance of L-asparaginase from the thermophilic Geobacillus kaustophilus (GkASNase). The experimental findings were further supported by computationally integrated tools such as homology modeling, docking, and molecular dynamics (MD) simulations. Among the selected osmolytes (maltose, sorbitol, trehalose, glycine, and sucrose), GkASNase showed the highest stability during 30 days of storage in the presence of maltose and arginine. Maltose increased GkASNase activity approximately 2-fold at 37 °C and 55 °C. In the presence of osmolytes, the K_m values of GkASNase decreased and the V_max values increased compared to controls at 37 °C and 55 °C. In the presence of osmolytes, the acrylamide mitigation performance of GkASNase increased by 1.7-fold in a 15 min reaction. The computational analysis indicates that L-asparagine as substrate enhances protein compactness and stability, while arginine as osmolyte increases flexibility and optimizes water distribution around the enzyme. These findings provide novel insights into enzyme stabilization that have implications for therapeutic and biotechnological applications.